001 /*
002 * Cumulus4j - Securing your data in the cloud - http://cumulus4j.org
003 * Copyright (C) 2011 NightLabs Consulting GmbH
004 *
005 * This program is free software: you can redistribute it and/or modify
006 * it under the terms of the GNU Affero General Public License as
007 * published by the Free Software Foundation, either version 3 of the
008 * License, or (at your option) any later version.
009 *
010 * This program is distributed in the hope that it will be useful,
011 * but WITHOUT ANY WARRANTY; without even the implied warranty of
012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
013 * GNU Affero General Public License for more details.
014 *
015 * You should have received a copy of the GNU Affero General Public License
016 * along with this program. If not, see <http://www.gnu.org/licenses/>.
017 */
018 package org.cumulus4j.store.query.method;
019
020 import java.util.Collection;
021 import java.util.HashMap;
022 import java.util.HashSet;
023 import java.util.Map;
024 import java.util.Set;
025
026 import javax.jdo.Query;
027
028 import org.cumulus4j.store.crypto.CryptoContext;
029 import org.cumulus4j.store.model.FieldMeta;
030 import org.cumulus4j.store.model.IndexEntry;
031 import org.cumulus4j.store.model.IndexEntryFactory;
032 import org.cumulus4j.store.model.IndexValue;
033 import org.cumulus4j.store.query.QueryEvaluator;
034 import org.cumulus4j.store.query.eval.ExpressionHelper;
035 import org.cumulus4j.store.query.eval.InvokeExpressionEvaluator;
036 import org.cumulus4j.store.query.eval.PrimaryExpressionResolver;
037 import org.cumulus4j.store.query.eval.ResultDescriptor;
038 import org.datanucleus.query.expression.Expression;
039 import org.datanucleus.query.expression.PrimaryExpression;
040 import org.datanucleus.store.ExecutionContext;
041
042 /**
043 * Evaluator for "String.substring(pos1 [, pos2]) {oper} {compareTo}".
044 */
045 public class StringSubstringEvaluator extends AbstractMethodEvaluator {
046
047 /* (non-Javadoc)
048 * @see org.cumulus4j.store.query.method.AbstractMethodEvaluator#requiresComparisonArgument()
049 */
050 @Override
051 public boolean requiresComparisonArgument() {
052 return true;
053 }
054
055 /* (non-Javadoc)
056 * @see org.cumulus4j.store.query.method.MethodEvaluator#evaluate(org.cumulus4j.store.query.QueryEvaluator, org.cumulus4j.store.query.eval.InvokeExpressionEvaluator, org.datanucleus.query.expression.Expression, org.cumulus4j.store.query.eval.ResultDescriptor)
057 */
058 @Override
059 public Set<Long> evaluate(QueryEvaluator queryEval,
060 InvokeExpressionEvaluator invokeExprEval, Expression invokedExpr,
061 ResultDescriptor resultDesc) {
062 if (invokeExprEval.getExpression().getArguments().size() < 1 || invokeExprEval.getExpression().getArguments().size() > 2)
063 throw new IllegalStateException("String.substring(...) expects 1 or 2 arguments, but there are " +
064 invokeExprEval.getExpression().getArguments().size());
065
066 // Evaluate the invoke argument
067 Object[] invokeArgs = ExpressionHelper.getEvaluatedInvokeArguments(queryEval, invokeExprEval.getExpression());
068
069 if (invokedExpr instanceof PrimaryExpression) {
070 return new MethodResolver(invokeExprEval, queryEval, (PrimaryExpression) invokedExpr, invokeArgs[0],
071 (invokeArgs.length > 1 ? invokeArgs[1] : null),
072 compareToArgument, resultDesc.isNegated()).query();
073 }
074 else {
075 if (!invokeExprEval.getLeft().getResultSymbols().contains(resultDesc.getSymbol()))
076 return null;
077
078 return queryEvaluate(invokeExprEval, queryEval, resultDesc.getFieldMeta(), invokeArgs[0],
079 (invokeArgs.length > 1 ? invokeArgs[1] : null), compareToArgument, resultDesc.isNegated());
080 }
081 }
082
083 private Set<Long> queryEvaluate(
084 InvokeExpressionEvaluator invokeExprEval,
085 QueryEvaluator queryEval,
086 FieldMeta fieldMeta,
087 Object invokeArg1, // the xxx1 in 'substring(xxx1)'
088 Object invokeArg2, // the xxx2 in 'substring(xxx1, xxx2)'
089 Object compareToArgument, // the yyy in 'substring(...) >= yyy'
090 boolean negate
091 ) {
092 CryptoContext cryptoContext = queryEval.getCryptoContext();
093 ExecutionContext executionContext = queryEval.getExecutionContext();
094 IndexEntryFactory indexEntryFactory = queryEval.getStoreManager().getIndexFactoryRegistry().getIndexEntryFactory(
095 executionContext, fieldMeta, true
096 );
097
098 Query q = queryEval.getPersistenceManagerForIndex().newQuery(indexEntryFactory.getIndexEntryClass());
099 q.setFilter(
100 "this.fieldMeta == :fieldMeta && " +
101 (invokeArg2 != null ?
102 "this.indexKey.substring(" + invokeArg1 + "," + invokeArg2 +") " :
103 "this.indexKey.substring(" + invokeArg1 + ") ") +
104 ExpressionHelper.getOperatorAsJDOQLSymbol(invokeExprEval.getParent().getExpression().getOperator(), negate) +
105 " :compareToArgument"
106 );
107 Map<String, Object> params = new HashMap<String, Object>(2);
108 params.put("fieldMeta", fieldMeta);
109 params.put("compareToArgument", compareToArgument);
110
111 @SuppressWarnings("unchecked")
112 Collection<? extends IndexEntry> indexEntries = (Collection<? extends IndexEntry>) q.executeWithMap(params);
113
114 Set<Long> result = new HashSet<Long>();
115 for (IndexEntry indexEntry : indexEntries) {
116 IndexValue indexValue = queryEval.getEncryptionHandler().decryptIndexEntry(cryptoContext, indexEntry);
117 result.addAll(indexValue.getDataEntryIDs());
118 }
119 q.closeAll();
120 return result;
121 }
122
123 private class MethodResolver extends PrimaryExpressionResolver
124 {
125 private InvokeExpressionEvaluator invokeExprEval;
126 private Object invokePos1;
127 private Object invokePos2;
128 private Object compareToArgument;
129 private boolean negate;
130
131 public MethodResolver(
132 InvokeExpressionEvaluator invokeExprEval,
133 QueryEvaluator queryEvaluator, PrimaryExpression primaryExpression,
134 Object invokeArg1, // the xxx in 'substring(xxx) >= yyy'
135 Object invokeArg2, // the xxx in 'substring(xxx1, xxx2) >= yyy'
136 Object compareToArgument, // the yyy in 'substring(xxx) >= yyy'
137 boolean negate
138 )
139 {
140 super(queryEvaluator, primaryExpression);
141 this.invokeExprEval = invokeExprEval;
142 this.invokePos1 = invokeArg1;
143 this.invokePos2 = invokeArg2;
144 this.compareToArgument = compareToArgument;
145 this.negate = negate;
146 }
147
148 @Override
149 protected Set<Long> queryEnd(FieldMeta fieldMeta) {
150 return queryEvaluate(invokeExprEval, queryEvaluator, fieldMeta, invokePos1, invokePos2, compareToArgument, negate);
151 }
152 }
153 }